The invention broadly relates to a device that is useful in, for example, heat or mass transfer, the separation of gases by absorption or desorption, the concentration of fluids, catalytic reactions, or particle cleaning. Such a device is especially suitable for use as a heat wheel or rotary recuperator in which, for example, heat energy from hot exhaust flue gas is captured and used to preheat combustion air or hot gas used in a particular process from which the hot exhaust gas is being removed.
Rotary recuperators or heat wheels are well known and used in the exchange of thermal energy between hot and cool gases. Generally, such devices employ stationary hot and cold gas chambers through which a rigid, preformed, torus-shaped heat wheel is rotated to be alternately heated and cooled by the gases being circulated through the device. The heat wheel is composed of thermal energy responsive material, e.g. honeycombed ceramic-type material, through which the hot and cool gases are circulated to achieve a thermal energy exchange between the gases and material.
A serious problem of such devices is in the provision of a good effective seal between the stationary hot and cold gas chambers and the rotary heat wheel which, because of a pattern of alternating heating and cooling, has portions that are constantly expanding and contracting in such a way as to cause continual warping and distortion of the heat wheel thereby making it exceedingly difficult for the seal to maintain contact with the rotary wheel. Thus, it is not uncommon for such devices to experience gas leakage between the two stationary chambers, which leakage generally disrupts the heat exchanging process when the seals become the least bit worn and ineffective. The invention is primarily designed to overcome this problem by the provision of a heat exchanging device in which it is not necessary to maintain a seal in contact with the thermal energy responsive material.
Briefly stated, the invention is in a device which comprises a stationary, hollow, cylindrical fluid distributing member and a hollow closed torus-shaped rotary member which is mounted for rotation about the stationary member in a plane which is generally normal to the longitudinal axis of the stationary member. The stationary member is longitudinally and transversely divided into four compartments, through which fluid is circulated between pairs of longitudinally communicating compartments. The rotary member is divided into pie-shaped sections or chambers which carry material through which fluid can be circulated. A plurality of longitudinally extending wiper-type seals and circumferentially oriented ring seals are positioned in the space between the rotary and stationary members and divide the space into four segments which are in communication with the four compartments of the stationary member. The seals literally divide the device into two chambers through which different fluids can be simultaneously circulated free of each other. The compartments of the stationary member and the sections of the rotary member are provided with communicating openings so that one fluid can be circulated through a first pair of compartments and communicating sections while another fluid is circulated through the second pair of compartments and communicating sections.
It can be appreciated that it is much simpler to provide good effective seals between the inner periphery of the rotating closed torus and the adjacent outer periphery of the stationary cylinder, than it is to provide good, continuous contact of a flap seal with a twisting heat wheel of the prior art. In addition, the device of the invention has the added advantage of not being restricted in the shape or size of, for example, the thermal energy responsive material that is carried by the rotary member. Most heat wheels are preformed of thermal responsive material into a comparatively rigid ring, but this is understandable, since it is the rotating member. The rotary member of this invention carries and supports the thermal energy responsive material which can be composed of any suitable loosely or tightly packed particulate material as well as having the more rigid structure previously described.